OCE Informal Document No. 42 Thirteenth Plenary Meeting of the Working Group On Off-Cycle Emissions 5 & The Hague, Netherlands WNTE WNTE control area evaluation with respect to the real-world engine operation envelope TNO Knowledge for Business Iddo Riemersma, 13 th plenary meeting of the Off-Cycle Informal Working Group, 5-7 April 2006
Introduction Main question: Is the proposed WNTE control area sufficiently wide enough? or Are there spots in the engine map (outside the proposed control area) that have a significant contribution in real life operation emissions? and if so, If/how could these points be added to the proposed control area? 2
Presentation overview I. Review of lower engine speed limit of the II. Methodology for calculating emission contributions III. Preliminary results for typical cases of vehicle and application IV. Further steps: WNTE evaluation project for DG Enterprise 3
WNTE control area (work.doc. version 8) Normalised Normalised engine engine torque torq 1,2 1 0,8 0,6 0,4 0,2 max. torque 30% power 70% power A, B and C speed PM carve-out 0 0 0,2 0,4 0,6 0,8 1 1,2 1,4 Normalised engine speed 4 Control area for average Euro 3 engine Lower speed limit based on US NTE approach at n lo +0.15(n lo +n high )
WNTE control area (work.doc. version 9) 1,2 1 max. torque 30% power 70% power A, B and C speed Normalised engine torq Normalised engine torque 0,8 0,6 0,4 0,2 PM carve-out 0 0 0,2 0,4 0,6 0,8 1 1,2 1,4 Normalised engine speed Control area for average Euro 3 engine 5 Lower speed limit is 25 th percentile of cum. frequency for WHTC incl. idle
WHTC cumulative frequency including idle 100% 90% 80% cumulative frequency 70% 60% 50% 40% 30% 31% 20% 10% 29% 0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% n norm 6
WHTC cumulative frequency excluding idle 100% 90% 80% cumulative frequency 70% 60% 50% 40% 30% 20% 10% 37% 35% 0% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% n norm 7
Conclusion on NTE lower engine speed limit 25 th percentile (including idle) is close to the bend of the curve Increase to 30 th percentile is more safe while lower limit increase is only small Lower limit for 25 th percentile excluding idle is higher than 30 th percentile including idle 8
II. Methodology for calculating emission contribution 1. Determine the WNTE area for an average engine 2. Simulate a number of representative cases (representative vehicle types over representative real-life driving cycles) 3. Calculate the emission contribution for each part of the engine map 4. Evaluate the emission contributions in- and outside the control area 5. Consider whether an extension of the is rational against the emission map 9
NO x emission map in [g/h] for average Euro 3 Relative NOx emission 0.9 0.7 Engine torque (norm.) 0.5 0.3 0.1 0.0-0.1 00 Engine: Euro 3 (average) 10-0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.)
PM emission map in [g/h] for average Euro 3 Relative PM emission 0.9 0.7 Engine torque (norm.) 0.5 0.3 0.1 0.0-0.1 00 Engine: Euro 3 (average) 11-0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.)
Simulated city driving cycle for truck with trailer (second by second) Normalised engine torq Normalised engine torque 1,2 1 0,8 0,6 0,4 0,2 load points 30% power 0-0,2 0 0,2 0,4 0,6 0,8 1 1,2 1,4-0,2 Normalised engine speed 12
Grid is placed over the engine map Normalised engine torq torque 1,2 1,1 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 load points 30% power 0-0,1-0,1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,1 1,2 1,3-0,2 Normalised engine speed 13
Emission contribution per box is calculated Contribution is sum of momentaneous emissions 1,2 for loadpoints 1,1 in the box 1 Normalised engine torq torque 0,9 load points 30% power 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0-0,1-0,1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,1 1,2 1,3-0,2 Normalised engine speed 14
Relative NOx contribution Graphical representation 0.9 0.7 Engine torque (norm.) 0.5 0.3 0.9 0.7 Relative NOx emission 0.1 0.0-0.1 00-0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.) Vehicle: Truck with trailer Engine: Euro 3 (average) Driving cycle: City Shifting: Economic/fast Normalised engine torq 15 1,2 1,1 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0-0,1-0,1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,1 1,2 1,3-0,2 Normalised engine speed Engine torque (norm.) 0.5 0.3 load points 30% power 0.1 0.0-0.1 00 Engine: Euro 3 (average) - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.)
III. Results for typical cases Truck with trailer on Urban road Rural road Motorway City bus on an urban road Based on (average) Euro 3 emission map 16
Results for NO x and PM (truck/trailer in motorway driving) Relative NOx contribution Relative PM contribution 0.9 0.9 0.7 0.7 Engine torque (norm.) 0.5 0.3 Engine torque (norm.) 0.5 0.3 0.1 0.1 0.0-0.1 00 Vehicle: Truck with trailer Engine: Euro 3 (average) Driving cycle: Motorway Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 0.0 Vehicle: Truck with trailer Engine: Euro 3 (average) -0.1 00 Driving cycle: Motorway Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.) Engine speed (norm.) 17
Results for NO x and PM (truck/trailer in city driving) Relative NOx contribution Relative PM contribution 0.9 0.9 0.7 0.7 Engine torque (norm.) 0.5 0.3 Engine torque (norm.) 0.5 0.3 0.1 0.1 0.0-0.1 00 Vehicle: Truck with trailer Engine: Euro 3 (average) Driving cycle: City Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 0.0 Vehicle: Truck with trailer Engine: Euro 3 (average) -0.1 00 Driving cycle: City Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 18 Engine speed (norm.) Carve-out below 30% power excludes a high emission contribution area (for this particular case) Emission contribution in carve-out for PM is rather low Engine speed (norm.)
Results for different cases contribution (excl. 30 sec. interval) Idle contribution 90 30 80 70 25 60 20 [%] 50 40 Share in NOx contribution PM contribution [%] 15 Idle share NOx contribution PM contribution 30 10 20 10 5 0 truck and trailer (city) truck and trailer (rural) truck and trailer (motorway) urban bus (city) 0 truck and trailer (city) truck and trailer (rural) truck and trailer (motorway) urban bus (city) NTE share could be increased by a larger 19
Relative NOx emission [g/kwh] - 0.0 Engine torque (norm.) 1.2-0.0 Engine speed (norm.) 20 Engine: Euro 3 (average)
Relative NOx emission [g/kwh] Relative NOx emission (normalised g/kwh) 0.9 0.7 normalised engine torque 0.5 0.3 0.1 Engine torque (norm.) Engine speed (norm.) 21 0.0 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 normalised engine speed Engine: Euro 3 (average)
Preliminary conclusions Time share of engine operation in rather low Emission contribution in is considerably higher Emission contribution of idle operation is comparatively low Carve-out below 30% power excludes a high emission contribution area (depending on the vehicle application) Carve out for PM seems unnecessary BUT: this is only concluded on a limited dataset. Further research is needed and will be executed during a study for DG Enterprise 22
IV. Further steps: WNTE evaluation for DG Enterprise Purpose: to appraise the suitability to European engines and driving conditions of the draft WNTE control zone concept (OCE GTR) Funded from the DG-ENT framework contract on Economic and technical assistance in relation to the emission of environmental pollutants from automobiles Project team: TNO Automotive (NL) TÜV Nord (D) TU Graz (A) EMPA (CH) 23
Project scope TASK 1 Assessment of WNTE concept in current GTR Existing driving patterns data for representative categories of vehicle type and application (from WHDC database) Simulation of PM and NO x emissions per category using current PHEM model (Euro 3 engine map) Graphical presentation of emissions in/outside the NTE control zone 24
Project scope Output of Task 1: Timeshare in/outside the NTE control zone Positive work in/outside the NTE control zone Emissions in/outside the NTE control zone Effect of interval length on these shares of time/work/emissions 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Time [s] Positive Engine Work [kwh] Cumulated emissions (with 30 seconds rule) [g] Cumulated emissions (without 30 seconds rule) [g] 25 within W outside W
Project scope TASK 2 Assessment of NTE concept for future HD engines Based on: Limited amount of existing data for Euro 4/5 engines (quantitative) Expert views on Euro 5/6 engines behaviour/calibration (qualitative) Resulting in: Identifying possible limitations in proposal TASK 3 Review of the effectiveness of WHDC and WNTE concepts as a whole Coverage of higher risk areas Elimination of defeat devices and/or irrational control strategies Identifying possible limitations 26
Project scope TASK 4 Consider rationale for improving NTE definitions: Changing engine speed limit of Review of carve outs (e.g. 30% power, PM carve out) 30 seconds interval Review of compliance factor (1.25, 1.5 or other) TASK 5 Assessment of ambient temperature and pressure boundaries Analysis of existing on-road measurements Expert view for future engine technology TASK 6 Review of alternative NTE concepts Including (but not limited to): Work-based window Compliance factor (based on BSFC instead of torque) 27
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Results for NO x and PM (truck/trailer in rural driving) Relative NOx contribution Relative PM contribution 0.9 0.9 0.7 0.7 Engine torque (norm.) 0.5 0.3 Engine torque (norm.) 0.5 0.3 0.1 0.1 0.0-0.1 00 Vehicle: Truck with trailer Engine: Euro 3 (average) Driving cycle: Rural Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 0.0 Vehicle: Truck with trailer Engine: Euro 3 (average) -0.1 00 Driving cycle: Rural Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.) Engine speed (norm.) 29
Results for NO x and PM (city bus in urban driving) Relative NOx contribution Relative PM contribution 0.9 0.9 0.7 0.7 Engine torque (norm.) 0.5 0.3 Engine torque (norm.) 0.5 0.3 0.1 0.1 0.0-0.1 00 Vehicle: City bus Engine: Euro 3 (average) Driving cycle: City Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 0.0 Vehicle: City Bus Engine: Euro 3 (average) -0.1 00 Driving cycle: City Shifting: Economic/fast - 0.0 0.1 0.3 0.5 0.7 0.9 1.1 1.2 1.3 1.4 Engine speed (norm.) Engine speed (norm.) 30